The use of printed wiring boards, also known as printed circuit boards, for supporting plural electrical components is wide spread in many electronic fields. These printed circuit boards typically are formed of an insulated substrate having etched conductive traces thereon which serve to interconnect other components both active and passive, which form the electronic circuit assembly. In order to connect one of these printed circuit boards to another or to another external electrical component electrical connectors are typically used. In order to permit the electrical connector to interface with the printed circuit board a header is disposed on the printed circuit board at a selected location and connected by traces to the remainder of the components supported on the board. The header typically includes an insulative housing having plural elongate electrical contacts. One end of the contacts is electrically and mechanically supported to the printed circuit board while the other end of the contacts is exposed for external electrical connection.
It has been noted that often the printed circuit board assembly may be adversely effected by external environmental influences such as dust, dirt or moisture. Therefore, the entire printed circuit board assembly including the header or headers attached thereto is typically subjected to a conformal coating process. This conformal coating, which may be disposed in a number of various manners such as by dipping the printing wiring board in a coating bath or spraying the coating thereover, forms a protective barrier to adverse environmental hazards which may act negatively on the electrical circuitry on the board. This conformal coating is preferably an insulative coating thereby preventing any short circuiting between electrical components supported on the board. One problem that has been noted with the use of conformal coating is that the insulative coating may adhere to electrically conductive areas such as the conductive terminals of the header, which are to remain non-insulated. Thus, before the header can be connected to another electrical connector the conformal coating must be removed from the electrical terminals of the header.
It can be appreciated that it would be advantageous to prevent the conformal coating from covering the terminals of the header during the coating process. However, there is no adequate existing technique to provide a covering for the header contacts while still permitting the conformal coating to cover the remainder of the printed circuit board and components supported thereon. It is desirable to provide a method and apparatus for covering the terminals of the header prior to applying the conformal coating and then being able to remove that covering to expose the electrical contact for exterior electrical connection.